No one security suite does a good enough job. I'm sorry, but these suites are just not complete. Stand alone products, that are specific to a certain aspect of protection, offer better protection. Ex: product A for anti-virus, product B for antispyware, product C for antispam (if you use Outlook Express),etc.
If you have a Dual Core system (which are the latest until QUAD Core comes out in April) with a large amount of RAM, say 4GB (money not being the issue here), then really you can use any software you like regardless of what its impact might be on system resources because your system can handle it. You could buy into the "Best selling anti-virus software in the world" phrase on a certain company's website/product box and go down that road, BUT you can be sure that you will NOT be getting the BEST anti-virus software! The best ones aren't heard of, by most people but offer superior protection and consume less resources. They are from Eastern European countries, which becomes a major turn-off for a lot of people...are they real, what's their support like, how come nobody's heard of them are the types of questions you'll have to deal with if your'e considering buying one of those products. There are some from North America, besides the big 2 - McAfee and Norton, that can come close to the European unknowns but they too are just that.....unknown.
I've found that reputation sells a lot more stuff off the shelf, than product quality. McAfee and Norton are known to offer very good after sales customer support....nobody knows about the other smaller companies, hell they might not even offer a support line! The problem with those two is that they eat up a lot of system resources, causing a real slow down in system performance. I've found that they are really just good for anti-virus...they're no good for anti-spam, antispyware, etc.! However, the smaller ones also tend to specialize in one feature of Internet Security...anti-virus being the most popular one. There may be negligible differences in performance of the other (non antivirus) features of security suites, but I've found (through nothing other than personal evaluation of 30 day free trials) that most tend to specialize in virus protection...the other features are only there to make you feel better (safer) about the antivirus part.
For me, I’ve learnt the hard way that the best internet security is common sense. Combine that with one of the top 4 “light on your system” anti-virus programs from the site given below, Zone Labs’ Firewall and three lightweight On-demand (non-resident) anti-spyware scanners and you’re set. The rest of the features like anti-spam, shredder, etc. could come from just about anywhere as long as they doesn’t eat up the system’s resources.
There’s no perfect (one size fits all type of thing) internet security suite out there that is preferred….if you really MUST have an internet security suite, I would say that it would come down to personal preference. The big companies are are masters at advertising and come pre-installed on many new computers which leads a lot of people to just use them as they are already there. With some research and trialing you can come up with something better than those pretty easily. Security suites may make it easier to control everything from one interface and have a shorter learning curve, but as of now I believe no suite offers the best AV, Firewall, and Spyware Protection all-in-one which is why I choose to build my own. Every one has their own opinion on which is best, you probably know the old saying about opinions. Avg is a good program but at the same time there are reasons people purchase software instead of running the free apps.
Keep in mind this is my opinion and you should research and “trial” until you find what works for you. I'm not trying to tick off people who use McAfee or Norton, but in my experience they have proven to be less than stellar.
anti-virus-software-review.toptenreviews.com/
),stay off of warez sites 'cause they're usually full of worms and trojans and other basic security measures. 
sorry, my first "Soviet Russia" joke )
